The value of a cover crop is best seen below the soil surface. Dan Perkins, Jasper County SWCD (IN), shows the power of cover crop roots in this short, but informative video that was shot on April 8, 2013.  

Cover Crop Roots Near the Soil Surface

Dan notes that in the top 7 to 8 inches, the annual ryegrass roots are doing some amazing things. The roots are:

• increasing soil tilth
• providing food and habitat for biological life
• helping to control erosion
• allowing water to infiltrate through macro-pores, thus eliminating ponding and crusting
• holding on to the infiltrated water

These things are all extremely important because this, of course, is the primary zone where the cash crop will be feeding. But the annual ryegrass roots are also beneficial below the top few inches of the soil profile. 

Cover Crop Roots in the Yellow Sand Layer

While many farmers remain skeptical that cover crop roots can penetrate down into the "non-productive" parts of the soil profile, this video proves otherwise. Dan clearly shows that annual ryegrass roots:

• aggressively penetrate below the top soil area
• actively grow at 29 - 30 inches deep
• provide a nutrient rich rhizosphere

These root channels are producing organic matter, nutrient holding capacity, water holding capacity, and a channel for next year's corn roots to easily follow.  

It's all the stuff that you CAN'T see from the soil surface that is making the difference in the following year's cash crop.